﻿using UnityEngine;
using System.Collections;

[RequireComponent(typeof(SkeletonUtilityBone)), ExecuteInEditMode]
public class SkeletonUtilityGroundConstraint : SkeletonUtilityConstraint {

	[Tooltip("LayerMask for what objects to raycast against")]
	public LayerMask groundMask;
	[Tooltip("The 2D")]
	public bool use2D = false;
	[Tooltip("Uses SphereCast for 3D mode and CircleCast for 2D mode")]
	public bool useRadius = false;
	[Tooltip("The Radius")]
	public float castRadius = 0.1f;
	[Tooltip("How high above the target bone to begin casting from")]
	public float castDistance = 5f;
	[Tooltip("X-Axis adjustment")]
	public float castOffset = 0;
	[Tooltip("Y-Axis adjustment")]
	public float groundOffset = 0;
	[Tooltip("How fast the target IK position adjusts to the ground.  Use smaller values to prevent snapping")]
	public float adjustSpeed = 5;

	Vector3 rayOrigin;
	Vector3 rayDir = new Vector3(0,-1,0);
	float hitY;
	float lastHitY;

	protected override void OnEnable ()
	{
		base.OnEnable ();
	}

	protected override void OnDisable ()
	{
		base.OnDisable ();
	}

	public override void DoUpdate()
	{
		rayOrigin = transform.position + new Vector3(castOffset,castDistance,0);

		hitY = float.MinValue;
		if(use2D){
			RaycastHit2D hit;

			if(useRadius){
				hit = Physics2D.CircleCast( rayOrigin, castRadius, rayDir, castDistance + groundOffset, groundMask );
			}
			else{
				hit = Physics2D.Raycast(rayOrigin , rayDir, castDistance + groundOffset, groundMask);
			}

			if(hit.collider != null){
				hitY = hit.point.y + groundOffset;
				if(Application.isPlaying){
					hitY = Mathf.MoveTowards( lastHitY, hitY, adjustSpeed * Time.deltaTime );
				}
			}
			else{
				if(Application.isPlaying)
					hitY = Mathf.MoveTowards( lastHitY, transform.position.y, adjustSpeed * Time.deltaTime );
			}
		}
		else{
			RaycastHit hit;
			bool validHit = false;

			if(useRadius){
				validHit = Physics.SphereCast( rayOrigin, castRadius, rayDir, out hit, castDistance + groundOffset, groundMask );
			}
			else{
				validHit = Physics.Raycast( rayOrigin, rayDir, out hit, castDistance + groundOffset, groundMask);
			}

			if(validHit){
				hitY = hit.point.y + groundOffset;
				if(Application.isPlaying){
					hitY = Mathf.MoveTowards( lastHitY, hitY, adjustSpeed * Time.deltaTime );
				}
			}
			else{
				if(Application.isPlaying)
					hitY = Mathf.MoveTowards( lastHitY, transform.position.y, adjustSpeed * Time.deltaTime );
			}
		}

		Vector3 v = transform.position;
		v.y = Mathf.Clamp(v.y, Mathf.Min(lastHitY, hitY), float.MaxValue);
		transform.position = v;
		
		utilBone.bone.X = transform.localPosition.x;
		utilBone.bone.Y = transform.localPosition.y;

		lastHitY = hitY;

	}

	void OnDrawGizmos(){
		Vector3 hitEnd = rayOrigin + (rayDir * Mathf.Min(castDistance, rayOrigin.y - hitY));
		Vector3 clearEnd = rayOrigin + (rayDir * castDistance);
		Gizmos.DrawLine(rayOrigin, hitEnd);

		if(useRadius){
			Gizmos.DrawLine(new Vector3(hitEnd.x - castRadius, hitEnd.y - groundOffset, hitEnd.z), new Vector3(hitEnd.x + castRadius, hitEnd.y - groundOffset, hitEnd.z));
			Gizmos.DrawLine(new Vector3(clearEnd.x - castRadius, clearEnd.y, clearEnd.z), new Vector3(clearEnd.x + castRadius, clearEnd.y, clearEnd.z));
		}



		Gizmos.color = Color.red;
		Gizmos.DrawLine(hitEnd, clearEnd);
	}
}
